White balance processing device

Abstract

A white balance processing device comprises an amplifier which permits selection of one of a plurality of discrete amplification degrees; and an A-D converter the conversion gain which is variable by changing a reference voltage value. The selection of the amplification degree of the amplifier and the setting of the reference voltage value of the A-D converter are arranged to be performed in association with each other for continuous white balance control.

What is claimed is: 
     
       1. A white balance processing device comprising: a) a plurality of amplifiers for a plurality of color components, each of which is arranged to permit selection of an amplification degree thereof from among a plurality of discrete amplification degrees;   b) a plurality of analog-to-digital converters respectively coupled to the plurality of amplifiers for the plurality of color components, each said analog-to-digital converter arranged to have a conversion gain thereof variable by adjusting a reference voltage value; and   c) control means for continuously performing white balance adjustment by associating the selections of the amplification degree of said plurality of amplifiers and the adjusting of the reference voltage value for said plurality of analog-to-digital converters with each other.   
     
     
       2. A device according to claim 1, wherein each of said amplifiers is arranged to have a plurality of feedback resistance values. 
     
     
       3. A device according to claim 2, wherein said control means is arranged to select one of said plurality of feedback resistance values for each of said amplifiers. 
     
     
       4. A device according to claim 1, further comprising a color signal source arranged to supply said plurality of color components to said amplifiers. 
     
     
       5. A device according to claim 4, wherein said color signal source includes a color image sensor. 
     
     
       6. A device according to claim 5, wherein said color image sensor includes a combination of image sensing means and a color separation filter. 
     
     
       7. A color image sensing device comprising: a) color image sensing means;   b) control means for controlling white balance of a plurality of color components output from said color image sensing means, said control means including:   b-1) first gain control means for discretely controlling gains of the plurality of color components according to first control signals, said first gain control means including amplifiers and resistance means for feeding outputs of said amplifiers back to inputs of said amplifiers;   b-2) second gain control means for continuously controlling gains of the plurality of color components according to second control signals; and   b-3) a signal source for supplying said first and second control signals in a cooperative manner.   
     
     
       8. A device according to claim 7, wherein said first control signals are arranged to discretely change a resistance value of said resistance means. 
     
     
       9. A color image sensing device comprising: a) color image sensing means;   b) control means for controlling white balance of a plurality of color components output from said color image sensing means, said control means including:   b-1) first gain control means for discretely controlling gains of the plurality of color components according to first control signals;   b-2) second gain control means for continuously controlling gains of the plurality of color components according to second control signals, said second gain control means including analog-to-digital converters; and   b-3) a signal source for supplying said first and second control signals in a cooperative manner.   
     
     
       10. A device according to claim 9, wherein said color image sensing means includes at least one image sensor. 
     
     
       11. A device according to claim 10, wherein said color image sensing means includes at least one color separation filter. 
     
     
       12. A device according to claim 9, wherein said second control signals are arranged to change a reference voltage of said analog-to-digital converters. 
     
     
       13. A device according to claim 9, wherein said signal source is arranged to supply said first and second control signals in such a manner that changes in an overall gain caused by said first and second gain control means continuously takes place.